Work and the Human Body Lab / Name ______
Date ______
Essential Questions
1. What is the relationship between force and motion?
2. What does it look like when we do work? / Vocabulary
work, force, energy, Newton, joule / Objectives
1. Explain and investigate work, energy and force.
2. Contrast situations where work is done with different amounts of force to situations where no work is done.
Problem/Purpose: To investigate the scientific definition of work.
Background information: WORK is done when a force causes an object to move in the direction of the force. For work to be done, two things must occur. First, you must apply a force to an object. Second, the object must move in the same direction as the force you apply. If there is no motion, there is no work. This is very different from the way we use the word work in everyday life. Work can be calculated with this formula:
Work = Force X Distance
W = F d
UNITS OF MEASUREMENT:
Force: Newtons
Distance: Meters
Work: Joules (Newtons Meters)
Materials:
Lab Modified from: M. Poarch – 2003
http://science-class.net 3
4 books
3 different objects
Meter stick
Spring scale
Lab Modified from: M. Poarch – 2003
http://science-class.net 3
PART 1: OBSERVING WORK
Lab Modified from: M. Poarch – 2003
http://science-class.net 3
Procedure:
1. Stand and hold your arms out in front of you at waist level, palms up.
2. Have your partner stack two books on your hands, one on each hand.
3. Lift the books to about shoulder level, then lower them.
4. Now try raising them overhead. When your hands are overhead, are you working harder than when you raised them to shoulder level?
Describe your observations:
5. Lower the books again. Have your partner put two more books on each of your hands, so you’re holding four books. Try to raise them to shoulder level. Are you pushing harder (using more force) than when you were holding only two books?
Describe your observations:
6. Hold the four books at shoulder level until your arms get tired. Are you exerting force? Do you think you are doing work in these situations? What is the work being done on?
Describe your observations:
PART 2: Measuring Work
1. Attach one of the objects to the spring scale. Slowly lift or pull the object straight up. Record how much force (Newtons) you used to pull or lift the object on your data table.
2. Use the meter stick to measure the distance you moved the object. Record the distance in meters on your data table.
3. Find out how much work you did by using the formula: work = force x distance. Record your answer on your data table.
4. Repeat steps 1-3 with the other objects.
Data Table:
Calculations of WorkObject / Force (N) / Distance (m) / Work (J)
Conclude and Apply
1. What is a Joule?
2. Were you doing work when you were holding the books? Explain your answer.
3. Were you doing work when you were lifting object with the spring scale? Explain your answer.
4. In Greek mythology, Atlas held the world on his shoulders. Did he do any work? Explain your answer.
5. CHALLENGE: Identify 3 body systems directly involved doing the kind of work we did in this lab. Explain how each was involved.
Body System / How this system in involved in doing workLab Modified from: M. Poarch – 2003
http://science-class.net 3